Better Earthquake Warnings Within Reach, Scientists Say

SAN DIEGO — More accurate early warnings for dangerous tsunamis and powerful earthquakes could be within reach for the millions of people who live in vulnerable areas of the western United States, said scientists gathered here this week for the annual meeting of the Seismological Society of America.

In fact, researchers said, the instruments needed to produce better quake warnings are already in place; improving warnings simply requires adding information from GPS monitors to information delivered by vast networks of seismometers that dot the western United States, which are currently the sole provider of the data used to alert people in the moments before powerful shaking strikes.

"We depend on seismic networks for early warning, but they have limitations, especially for large earthquakes," said Yehuda Bock, a research geodesist and senior lecturer at Scripps Institution of Oceanography in La Jolla, Calif.  Bock pointed to Japan's devastating 2011 Tohoku earthquake and the deadly tsunami that followed as an example of the value of improved early warnings.

Although the Japanese have incredibly advanced earthquake and tsunami warning systems, they don't include GPS data in the mix — and GPS data can provide key information about the true magnitude of the most massive earthquakes.

Marrying the data

Seismometers close to an earthquake can pick up on the energy it released and transmit that information in real time to faraway places, providing warning before the ground shaking jolts a population center. However, seismometers aren't so good at accurately assessing magnitudes larger than 7. That's where GPS comes in. Though it takes a tiny bit longer to arrive at its first measurement, GPS is very good at assessing magnitude, because it literally measures how much the ground is moving.

"We're talking about real-time accuracy within centimeters," said Richard Allen, director of the Berkeley Seismological Laboratory.

When Japan's March 2011 earthquake struck offshore along a subduction zone — a type of fault where the ocean floor is grinding beneath another tectonic plate in a slow-motion dive — authorities estimated it was a magnitude 8 earthquake within about 120 seconds, said Walter Szeliga, a geodesist and research professor at Central Washington University. [7 Craziest Ways Japan's Earthquake Affected Earth]

"A magnitude 8 is a very large earthquake, but it's not expected to produce nearly as large a tsunami as you did have," Szeliga told OurAmazingPlanet. Combined seismic and GPS data would have revealed far more quickly that the quake was in fact a magnitude 9 — a quake about 30 times more powerful than a magnitude 8, he said.

"So an early warning is, in part, for shaking, but it's really useful for rapid tsunami alerts," Szeliga said.

The shadow of the March 2011 Tohoku disaster loomed large in discussions of how to improve warnings for the United States, which, like Japan, has the dubious distinction of sitting right next door to a fault — the Cascadia subduction zone — which is capable of producing the most powerful kinds of earthquakes on the planet.

Twofold threats

However, the seismological situation for the United States is a bit more complicated than it is for Japan, Allen told OurAmazingPlanet.

"They are mostly concerned about offshore earthquakes," Allen said. The United States faces threats not only from offshore earthquakes along the Cascadia fault, but also from those that hit on land — so-called strike-slip quakes, the sort produced by the San Andreas fault.

"That's why we're a little behind them," Allen said. "We need faster methodology because our cities are right on top of the faults."

He said an early warning system using both GPS and seismic data is operational right now, and about 50 scientists and a few public and private entities have access to the warnings. The system would require more instruments if it were to be made public — a goal that Allen envisions reaching by 2015 if funding comes through. Current estimates put the price tag at about $150 million.

The system could alert people from a few seconds to tens of seconds to up to a minute before an earthquake hits, using real-time information streamed from instruments close to the spot where the sudden movement along a fault first began.

"When people experience an earthquake, they just experience the strong shaking at their location," Allen said. "But the earthquake probably started seconds or minutes earlier at some distant location; you use the instruments close to the epicenter to constrain its size, so people get a warning before they feel the shaking."

This story was provided by OurAmazingPlanet, a sister site to LiveScience.

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Will We Really Find Alien Life Within 20 Years? (SPACE.com)

At a June 27 press conference, Russian astronomer Andrei Finkelstein said that extraterrestrials definitely exist, and that we're likely to find them within two decades.

"The genesis of life is as inevitable as the formation of atoms," said Finkelstein, the director of the Russian Academy of Sciences' Applied Astronomy Institute in St. Petersburg. He was speaking at the opening of an international symposium on the search for extraterrestrial civilizations that was being held at the institute.

"There are fundamental laws which apply to the entire universe," Finkelstein was quoted as saying by the Interfax news agency. Because those fundamental laws allowed intelligent life to develop on Earth, they ought to engender intelligent life elsewhere, too, he reasoned.

Finkelstein pointed out that in recent years, astronomers have found more than 1,000 exoplanets —planets orbiting stars other than our own — some of which lie within their stars' "habitable zones," or the regions in which the temperature is right for water to exist as a liquid. Finkelstein said there will be life on such planets if there is water.

Furthermore, he conjectures that the Search for Extraterrestrial Intelligence (SETI), a worldwide effort to detect radio and optical signals sent our way by extraterrestrials, will find examples of that life within two decades. (Some media sources have interpreted Finkelstein's words to mean that we will communicate back and forth with aliens within that time. Actually, he only said that we will detect their signals.)  [10 Alien Encounters Debunked]

For Finkelstein's striking prediction to come true, certain conditions must be met: There must be a planet with an alien civilization that is capable of transmitting high-power radio or optical signals our way. That civilization needs to exist within 20 light-years of Earth and have been broadcasting those signals starting today, or earlier, in order to reach Earth within 20 light-years of today. (Or, if the civilization is farther away, then it needs to have broadcast long enough ago that it could reach here within 20 years.)

Though detecting life elsewhere in the cosmos sounds difficult, as it turns out, several astronomers believe that Finkelstein's 20-year prediction is realistic. In fact, they have an equation that takes into account all the conditions that must be met in order to find life on other planets, and according to the equation, 20 years is a pretty good estimate for when we'll find it.

Seth Shostak, the senior astronomer at the SETI Institute in Mountain View, Calif., the most well-known SETI program, estimated that intelligent life would be found in 25 years in a paper he wrote five years ago. "Maybe Finkelstein read my paper," Shostak told Life's Little Mysteries, a sister site to SPACE. He agrees that we'll detect alien signals within two decades. [Earth's 10 Wildest Attempts to Contact Aliens]

One in a million

Shostak explained that the SETI Institute has aimed its radio telescopes at a few thousand star systems over the past 50 years. (They didn't detect any "deliberate signals" sent by aliens.)  Assuming that technology will continue to improve, he thinks we will be able to check out 1 million stars over the next two decades, and that one in that million will have a habitable planet that has intelligent life capable of transmitting signals that are strong enough for us to detect.

While other planets in that million may have had life that was broadcasting radio or optical waves sometime in the past (but which has since been wiped out by an asteroid or some other cataclysm), or will broadcast signals in the future, approximately one of them will be doing so at just the right moment for us to hear or see them.

Shostak's number, 1 in a million, follows from what is known as the Drake Equation. It is a formula created by Frank Drake (also of the SETI Institute) that takes various factors into account to determine the number of intelligent and signal-transmitting civilizations in our galaxy. Drake and Shostak both calculate that there are 10,000 such civilizations transmitting signals at any given moment. Because there are 100 billion stars in the galaxy, the math says 1 in 10 million stars will be sending radio signals our way. "Because you can throw out a lot of stars," Shostak said, making smart choices about which ones are likely to have life, we should be able to find someone or something by searching just 1 million stars.

"If we haven't succeeded once we've done 10 million or 100 million stars by around 2050, then we've grossly overestimated the strength of their transmitters, or some other factor," Shostak said. "One reason we could fail is that there's nobody out there, but I would consider that a last resort."

Candidate planets

SETI can narrow down its search by directing its attention to stars that astronomers discover to have planets in their habitable zones. So far, 1,235 exoplanets have been found by NASA's Kepler spacecraft, a probe that surveys regions of space, collecting data from stars and their planets which scientists then analyze. [How Do Astronomers Find Alien Planets?]

According to Bill Borucki, a planetary astronomer at NASA Ames Research Center and the principal investigator of the Kepler mission, about 50 of the exoplanets that have been found so far are in their stars' habitable zones, and five of those could be rocky rather than gaseous. ("To have life, you probably have to have a solid surface to walk on," Borucki said.)

By induction — what's true of a subset of stars is likely to be true of the rest — "there must be on the order of a billion planets in our galaxy in the habitable zones of their stars," Borucki said. When he and his team identify habitable planets, they tell SETI to point its radio telescopes their way.

Borucki isn't as bold when it comes to specifying when life will be found, but he is optimistic: "I think there's a good chance that there's life in our galaxy. With so many habitable planets, it's hard to imagine that there wouldn't be. And I think that at some point we'll probably discover it. I hope that SETI does that soon."

Even more likely than finding intelligent life far off in the galaxy, Borucki thinks we'll find much simpler, bacterial life much closer to home. "NASA has a number of missions to Mars, and there may be primitive life there. They're talking about missions to Enceladus [a moon of Saturn] and Europa [a moon of Jupiter], both of which probably have subsurface oceans," he said. "I think those are wonderful places to look. I think we might find life in our solar system first."

The Europa Jupiter System Mission (EJSM), a mission to Jupiter and its icy moon, is proposed for a launch in 2020.

Little green men?

Finklestein made one other suggestion — that intelligent alien life forms would be humanoid. He reasoned that, because the laws of nature led life on Earth to evolve in the way it did, alien life forms would develop similarly. Like humans, they probably have two arms, two legs and a head, he said, adding that "they may have different color skin, but even we have that."

Are aliens really little green — or blue or red — men, as Hollywood and Finkelstein suggest?  Shostak doesn't think so. "All you have to do is go down to the zoo and look around. There aren't too many critters there that look a lot like us," he said. "The fact that we have two arms and two legs is a consequence of our evolutionary past: We happened to evolve from a four-lobed fish. Among critters on Earth, the most popular number of appendages is six, not four; they're called bugs."

Intelligent aliens probably do have heads and appendages, though. "Having a head seems to be a good thing. Lots of organisms have heads and it seems to be a very efficient model. Having appendages is also important," Shostak said. "If they were dolphins then they wouldn't build radio transmitters."

This article was provided by Life's Little Mysteries, a sister site to SPACE.com. Follow Life's Little Mysteries on Twitter @llmysteries, then join us on Facebook. Follow Natalie Wolchover on Twitter @nattyover.

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